1. Field of the Invention
This invention relates to aminocyclitol antibiotics of the gentamicin class, which are useful as antibacterial agents.
2. Description of the Prior Art
Daum et al. U.S. Pat. No. 3,972,930, issued Aug. 3, 1976, disclose 2-hydroxygentamicins C.sub.1, C.sub.2 and C.sub.1a and 5-deoxygentamicins C.sub.1, C.sub.2 and C.sub.1a, which are prepared in a fermentative process involving the incorporation, respectively, of D-streptamine and 2,5-dideoxystreptamine into the products using a particular mutant of Micromonospora purpurea, namely M. purpurea ATCC 31,119, and Daum et al. U.S. Pat. No. 3,982,996, issued Sept. 28, 1976, disclose the fermentative process for the preparation of the same 2-hydroxy- and 2,5-dideoxystreptamine components involving the incorporation either of an appropriate aminocyclitol, e.g. D-streptamine or 2,5-dideoxystreptamine, or certain non-nitrogen containing cyclitols, e.g. scyllo-inosose, scyllo-inosose pentaacetate or 2,4,5-trihydroxycyclohexanone (2,4-cis), using a further mutant of M. purpurea ATCC 31,119, namely M. purpurea ATCC 31,164. However these patent disclosures do not describe the preparation of 5-deoxygentamicin C.sub.2b or 6'-N-methyl-2-hydroxy- or 6'-N-methyl-5-deoxygentamicins C.sub.2b , which are disclosed and claimed herein, and moreover the presently claimed compounds have not been isolated from, or detected in, the fermentation products obtained by the Daum et al. procedures disclosed in the two above-mentioned patents.
In fact the novel antibiotics of the present invention are produced by a different mutant of Micromonospora purpurea which, like M. purpurea ATCC 31,119 and M. purpurea ATCC 31,164, also incorporates D-streptamine and 2,5-dideoxystreptamine, but which surprisingly produces, so far as is known, none of the "major" components of 2-hydroxygentamicin and 5-deoxygentamicin, i.e. 2-hydroxygentamicins C.sub.1 and C.sub.2 and 5-deoxygentamicins C.sub.1 and C.sub.2 produced by the previous mutants, M. purpurea ATCC 31,119 and M. purpurea ATCC 31,164, but rather produces only 2-hydroxygentamicin C.sub.2b from D-streptamine and 5-deoxygentamicin C.sub.2b from 2,5-dideoxystreptamine as the major product in each case and lesser amounts of a second component, namely 6'-N-methyl-2-hydroxygentamicin C.sub.2b and 6'-N-methyl-5-deoxygentamicin C.sub.2b.
German Patent Application No. 2,821,948, published Dec. 7, 1978, discloses antibiotic XK-62-2, i.e. gentamicin C.sub.2b, O-[3-deoxy-4-C-methyl-3-methylamino-.beta.-L-arabinopyranosyl-(1.fwdarw.6) ]-O-[2-amino-6-methylamino-2,3,4,6-tetradeoxy-.alpha.-D-erythro-hexopyranos yl-(1.fwdarw.4)]-D-2-deoxystreptamine and antibiotic XK-62-4, O-[3-deoxy-4-C-methyl-3-methylamino-.beta.-L-arabinopyranosyl-(1.fwdarw.6) ]-O-[2-amino-6-dimethylamino-2,3,4,6-tetradeoxy-.alpha.-D-erythro-hexopyran osyl-(1.fwdarw.4)]-D-2-deoxystreptamine.
Daniels U.S. Pat. No. 4,117,221, issued Sept. 26, 1978, discloses certain 1-(.omega.-amino-.alpha.-hydroxy-loweralkanoyl) derivatives of gentamicins C.sub.1 and B.sub.1.